Highly recommend Maria's place if you're looking for an inexpensive but tidy place to use as a base, 5 minutes walk from Sukhumvit and Asok station.
The rooms are modest but clean and equipped with a queen size bed, storage and a separate adjoining bathroom and a laundry service is available. It's worth noting there is a little ambient noise.
In addition you can wander downstairs during the Jutharos restaurant opening hours and enjoy some fantastic food! Maria and her partner are great value and have excellent local knowledge.